资源描述：
《2012届高考英语二轮复习 阅读理解部分之限时训练（四）.doc》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
1、2012届高考英语二轮专题复习精品阅读理解部分之限时训练（四）阅读理解Abreathtakingtrickpotentiallyleftoverfromourancestorsmightbefoundinus—theabilitytosenseoxygenthroughourskin.Amphibians(两栖动物),animalssuchasfrogsthatcanlivebothonlandandinwater,havelongbeenknowntobecapableofbreathingthroughtheirskin.Infact,th
2、efirstknownlunglessfrogthatbreathesonlythroughitsskinwasdiscoveredrecentlyintheriversofBorneo.Nowthesameoxygensensorsfoundinfrogskinsandinthelungsofmammalshaveunexpectedlybeendiscoveredintheskinofmice.“Noonehadeverlooked,”explainedRandallJohnson,abiologistresearcher.Miceandf
3、rogsarequitedistantrelatives,sothefacttheyhavethesemolecules(分子)incommonintheirskinsuggeststheymightwellbefoundintheskinofothermammals,suchashumans.“Wehavenoreasontothinkthattheyarenotintheskinofpeopletoo,”Johnsonsaid.Thesemoleculesnotonlydetectoxygen,buthelpincreaselevelsof
4、vitalredbloodcells,whichcarryoxygenaroundthebody.Normalmicebreathinginairthatis10percentoxygen—adangerouslylowlevelsimilartoconditionsatthetopofMountEverest,andabouthalfthatofairatsealevel.However,micethathadtheoxygensensorHIF-1ageneticallyremovedfromtheirskinfailedtoproduce
5、thishormone(荷尔蒙)evenafterhoursofsuchlowoxygen.Thesefindings,iftheyholdtrueinhumans,suggestonecouldraisethelevelofoxygencirculatinginsidethebody.Thiscouldhelptreatlungdiseasesanddisorderssuchasanemia(贫血症)withoutinjectingdrugs,whichmakeupamultibillion-dollarmarket,Johnsonsaid.
6、Athletesalsooftentrytogetmoreoxygendeliveredtotheirmusclesinordertoimprovetheirperformance.Theyoftendothisbytrainingathighaltitudesorinlow-oxygentents.Thenewstudysuggeststheymightwanttoexposetheirskinaswellasbreathinginlow-oxygenairtoimprovetheirperformance.“It’shardtosaywha
7、texactlymightbedone,however—there’salotwedon’tknowyet,”Johnsonexplained.ThescientistsdetailedtheirfindingsintheApril18issueofthejournalCell.64.WhichofthefollowingstatementsisTRUEaccordingtothepassage?A.Johnsonbelievesthatoxygensensorsalsoexistinhumanskin.B.Peoplehavetosurfth
8、eInternettoreaddetailedfindings.C.Ithasbeenprovedthatthesefindingshelptreat
